1. Field of the Invention
The Invention relates to a process and apparatus for forming mailers as continuous strips for use in correspondence or in the distribution of confidential information (salary forms for example).
2. Description of Prior Art
Generally, such strips comprise bundles of continuous sheets, folded in accordeon or zig zag fashion of which each flat surface constitutes an individual "mailer". These "mailers" allow for printing on a printer such as a computer printer, with an electronically readable or other material. The lower sheet of the bundle or sheet is adapted to form for each of the flat surfaces, i.e., for each of the unitary mailers, the backing of the mailer, while the upper sheet forms the face of the mailer. All of the intermediate sheets are adapted to constitute the interior documents or inserts of each of the mailers. In known assemblies (carbon papers, chemically treated papers, or self reproduction sheets which may be zoned, etc.) the strike of the printer is registered selectively on certain of the sheets, thus on certain of the interior documents, while non-personalized references, i.e., references which are identical for all of the mailers, are printed on one or several sheets before their assembly. Very often the bundle further comprises a cover band or strip known as an archive or verification strip, which covers the upper sheet. Originally, this band was principally adapted to register all of the information printed by the printer so as to allow for possible ultimate verification (thus the designation "verification" band). However, modern computer memory capacity renders this function unnecessary and the verification band serves only to "retain" the information which is not to appear on the upper sheet, i.e., most often all of the information besides the addresses of the addressee which are printed on the upper sheet by virtue of carbon sheets carefully positioned on the opposite side of the verification band.
At least the lower and upper sheets are joined by adhesive along the length of their lateral edges. Furthermore, each of the sides of the mailer is sealed at the top and bottom by transverse adhesive streams connecting the upper and lower sheets to one another across the transverse cutaways provided along all of the intermediate sheets.
Perforated detachment lines and/or tear tabs allow for the opening of the mailers by the addressees and the removal of the interior documents.
Finally, on each of its lateral sides, the bundle is provided with feeder perforations positioned in a marginal detachable zone. These perforations allow for the movement of the bundle in and through the printer and subsequently into the separation device.
After passage through the printer the bundle is brought to a separation device where, after removal of the cover strip, if one is used, the mailers are separated from one another along the zig zag fold lines either by rupture by exertion of traction or by cutting with a paper cutter or the like. Often, at the inlet of the separation device, serrated wheels longitudinally detach the marginal zones comprising the feeder perforations. However, such an arrangement is not absolutely necessary since the separation of these zones can be performed on each mailer by the addressee if longitudinal lines of detachable performations have been provided.
Numerous types of such individual mailer assemblies are known. These assemblies differ in some cases by the disposition of the interior documents. However, most often these assemblies differ in the disposition of the perforated detachment lines and of the tear tabs in a manner so as to allow for simplification of the technique used to open the mailer and to remove the inserts.
Such assemblies are being utilized more and more frequently for the distribution of confidential personalized information or for mass mailings such as advertising, late notices, bills, statements of account, payments, etc. However, all such assemblies suffer from certain disadvantages:
(a) Since each of the inserts is not in the position of the original, they cannot be used with magnetic or optical readers which makes the use of such articles impossible in particular with respect to the mailing of drafts and the like.
(b) As was noted above, a cover strip must be provided when certain data printed by the printer is not to be reproduced on the face of the envelope but is to appear on the inserts, which is most often the case. In such cases, this band is useless and is, therefore, disposed of almost immediately.
(c) In order to allow for clear reading of printer print on the interior documents and especially on the last document, it is necessary to use as the top sheet (face of the envelope) a low weight paper which is incompatible with certain situations, e.g., with mailers which are to be sorted by the post office.
(d) The transverse cutting of the intermediate sheets require costly additional steps requiring a special and costly tool.
(e) The cutaways cause a localized excess thickness in the corners due to the intermediate or insert sheets which results in the formation, during folding, of elevated areas and thus the risk of accident and of damage during passage through the printer.
In order to overcome the disadvantages set forth in subparagraphs (d) and (e), it has been proposed to make the interior documents (or inserts), not out of continuous intermediate sheets appropriately cut apart, but out of sections having dimensions smaller than those of a single mailer and adhesively secured on the continuous band formed by the lower sheet (U.S. patent application Ser. No. 720,398 now U.S. Pat. No. 4,239,114 and U.S. Pat. No. 4,095,695). These assemblies are nevertheless difficult to manufacture. In some cases, such difficulties occur by virtue of the stepwise progression through the assembly machine and always results in a noticeable slowdown of the production line.
In order to overcome the disadvantages of paragraphs (a), (b) and (c) it has been proposed to provide for the sealing of the individual mailers by the user, after the passage through the printer, which allows for the direct printing of at least one interior document and the obviation of the verificiation strip, either with a bundle of continuous sheets with conventional transverse cutaways (U.S. application Ser. No. 837,339 now abandoned), or according to certain of the embodiments disclosed in application Ser. No. 720,398 referred to above.